1. Field of the Invention
A pliers-type stripping tool includes a base, a pair of pivot levers pivotally connected with the base, a pair of clamping members connected for relative longitudinal displacement on one of the pivot levers, a pair of cutting members connected for relative longitudinal displacement on the other of said pivot levers, first and second spring means biasing apart the clamping jaws and the cutting jaws, respectively, and first operating means including a pair of pivotally connected handles operable to displace the clamping and cutting jaws together from their normal separated conditions toward adjacent positions in engagement with an insulated conductor positioned therebetween. Owing to the spring biasing means, a certain degree of tolerance is provided to compensate for variations in the diametric dimensions of the insulated conductor components. The cutting members sever a length of the insulation layer, and second operating means are operable by the handles to separate the pivot levers, thereby to strip from the bare conductor the length of severed insulation.
2. Brief Description of the Prior Art
Insulation stripping tools of the pliers type are well known in the prior art, as evidenced, for example, by the German patent No. DE 79 33 957 U1. This tool includes two clamping jaws and two stripping knives which operate in a pulling manner, that is to say, one clamping jaw each and a stripping knife are pulled in case of activation against a fixed clamping jaw and a fixed stripping knife. The movable clamping jaw and the stripping knife are not coupled together so that the movable clamping jaw and the stripping knife can be applied against the conductor independently of each other.
It is also known that one can provide a two-knife arrangement including two stripping knives each on stripping pliers that are arranged “back to back” with adjacent cutting areas. This can be advantageous because one does not leave any imprint of the clamping jaws on the conductor, which, under certain circumstances, could even damage the conductor, and because the very sharp knives can securely prevent the conductor from slipping through. On the other hand, separation with the two knife arrangement, positioned back to back, consisting of two stripping knifes each, is not always advantageous because that can result in an unsightly cutting result. The known stripping tools of this pliers design have the disadvantage that they have an extensively asymmetrical structure, something that makes production more expensive due to the large number of required parts and, moreover, the user finds handling this device to be rather difficult.
The present invention was developed to provide an improved pliers-type insulation stripping tool by means of which, using appropriate handling procedures, it is possible in a simple manner to provide a tolerance compensation for varying conductor diameters. Preferably, as an alternative, there is provided both a design with two clamping jaws and two stripping knives as well as an arrangement with an arrangement including two knives lying next to each other with two stripping knives each.
A certain degree of play is provided between the clamping and/or the cutting jaws due to the resilient action of a spring means with some degree of play in each case, which play is so designed that conductor tolerances, when clamping a conductor or when cutting the insulation end, can be equalized in a resilient manner.
According to manufacturer's data, conductors with the same nominal cross-section also differ somewhat from each other individually because, for instance, a single-wire, fine-wire, or multi-wire conductor may display a somewhat varying diameter. Therefore, the additional resilient arrangement also of the upper clamping jaw and the upper stripping knife or two stripping knives will have an advantageous effect in terms of “tolerance equalization.”
It is possible to combine the advantages of a clamping jaw arrangement and a stripping knife arrangement with each other because, on the one hand, it is advantageous to cut the conductor only with one stripping knife pair in order to avoid an unsightly double cut and, on the other hand, it is advantageous to hold the conductor in a defined fashion with one clamping jaw pair. However, according to the state of the art, the absence of tolerance equalization for conductors that allegedly have the same cross-section turned out to be a problem. These problems are solved by the present invention in a simple and effective way. The pliers are distinguished by comfortable handling capability.
The present invention makes it possible also to provide a dual knife arrangement with two movable and two fixed stripping knives each or—in a particularly preferred manner—one clamping jaw arrangement with two clamping jaws and one knife arrangement with two stripping knives.